The Pensacola Mountains () are a large group of mountain ranges and peaks that extend in a northeast–southwest direction in the

Transantarctic Mountains The Transantarctic Mountains (abbreviated TAM) comprise a mountain range of uplifted rock (primarily sedimentary) in Antarctica which extends, with some interruptions, across the continent from Cape Adare in northern Victoria Land to Coats L ...

System, Queen Elizabeth Land region of Antarctica. They comprise the Argentina Range, Forrestal Range, Dufek Massif, Cordiner Peaks, Neptune Range, Patuxent Range, Rambo Nunataks and Pecora Escarpment. These mountain units lie astride the extensive Foundation Ice Stream and Support Force Glacier which drain northward to the Ronne Ice Shelf.

Discovery and naming

The Pensacola Mountains were discovered and photographed on 13 January 1956 in the course of a transcontinental nonstop plane flight by personnel of

United States Navy The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...

Operation Deep Freeze Operation Deep Freeze is the code name for a series of United States missions to Antarctica, beginning with "Operation Deep Freeze I" in 1955–56, followed by "Operation Deep Freeze II", "Operation Deep Freeze III", and so on. (There was an init ...

I from McMurdo Sound to

Weddell Sea The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha C ...

and return. They were named by the United States

Advisory Committee on Antarctic Names The Advisory Committee on Antarctic Names (ACAN or US-ACAN) is an advisory committee of the United States Board on Geographic Names responsible for recommending commemorative names for features in Antarctica. History The committee was established ...

(US-ACAN) for the U.S. Naval Air Station,

Pensacola, Florida Pensacola ( ) is a city in the Florida panhandle in the United States. It is the county seat and only incorporated city, city in Escambia County, Florida, Escambia County. The population was 54,312 at the 2020 United States census, 2020 census. ...

, in commemoration of the historic role of that establishment in training aviators of the United States Navy. The mountains were mapped in detail by

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

(USGS) from surveys and United States Navy air photos in 1956–67.

Geology

The Pensacola Mountains were originally continuous with the Ventana Mountains near

Bahía Blanca Bahía Blanca (; English: ''White Bay''), colloquially referred to by its own local inhabitants as simply Bahía, is a city in the Buenos Aires Province, Buenos Aires province of Argentina, centered on the northwestern end of the eponymous Blanc ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

, Cape Fold Belt in

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

, the Ellsworth Mountains (West Antarctica) and the Hunter-Bowen orogeny in eastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. The

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years f ...

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

Neptune Group rests unconformably on a Cambrian succession, and is overlain disconformably by the Dover

Sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

of the Beacon Supergroup. Within the Neptune Group is the Brown Ridge Conglomerate, Elliott Sandstone, Elbow Formation, and the Heiser Sandstone.

Western features

The Foundation Ice Stream flows through the western part of the range. File:Pecora Escarpment USGS.jpg, Pecora Escarpment, South tip of Patuxent Range File:Thomas Hills USGS.jpg, Patuxent Range. Rambo Nunataks to north File:C83052s5 Schmidt Hills.jpg, North part of Neptune range * Pecora Escarpment (), an irregular escarpment, long, standing southwest of Patuxent Range and marking the southernmost exposed rocks of the Pensacola Mountains. * Patuxent Range (), a major range of the Pensacola Mountains. It comprises the Thomas Hills, Anderson Hills, Mackin Table and various

nunatak A nunatak (from Inuit language, Inuit ) is the summit or ridge of a mountain that protrudes from an ice field or glacier that otherwise covers most of the mountain or ridge. They often form natural pyramidal peaks. Isolated nunataks are also cal ...

s and ridges bounded by the Foundation Ice Stream, Academy Glacier and the Patuxent Ice Stream. * Rambo Nunataks (), a loose chain of

s which lie northwest of Patuxent Range and extend along the west side of the Foundation Ice Stream for . * Neptune Range (), a mountain range, long, lying west-southwest of Forrestal Range in the central part of the Pensacola Mountains. The range comprises Washington Escarpment with its associated ridges, valleys and peaks, the Iroquois Plateau, the Schmidt Hills and Williams Hills.

Northern features

The northern part of the range is to the south of the Filchner–Ronne Ice Shelf. File:C82052s5 Ant.Map Cordiner Peaks.jpg, Cordiner Peaks, West part of Dufek Massif File:C82045s1 Ant.Map Davis Valley cropped.jpg, East part of Dufek Massif. North part of Forrestal Range File:Saratoga Table USGS.jpg, South part of Forrestal Range File:C82037s5 Ant.Map Argentina Range.jpg, Argentina Range * Cordiner Peaks (), a group of peaks extending over an area of standing southwest of Dufek Massif in the northern part of the Pensacola Mountains. * Dufek Massif (), a rugged, largely snow-covered

massif A massif () is a principal mountain mass, such as a compact portion of a mountain range, containing one or more summits (e.g. France's Massif Central). In mountaineering literature, ''massif'' is frequently used to denote the main mass of an ...

long, standing west of the Forrestal Range in the northern part of the Pensacola Mountains. * Forrestal Range (), a largely snow-covered

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have aris ...

, about long, standing east of Dufek Massif and the Neptune Range in the Pensacola Mountains. * Argentina Range (), a range of rock peaks and bluffs, long, lying east of the northern part of Forrestal Range in the northeastern portion of the Pensacola Mountains.

References

Sources

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